Japan's NHK aims to launch 8K DTT service

Digital terrestrial television viewers in Japan are now expected to gain 8K UHD TV from 2025.

While the UK's digital terrestrial television service Freeview can't offer every public service channel in HD, let alone anything in a higher resolution, Japan's public service broadcaster NHK has indicated it's working towards getting its "Super Hi-Vision" 8K services on terrestrial TV by the middle of the next decade.

The broadcaster already offers an 8K service via satellite, a much higher resolution version of UHD compared to that offered by Sky, Virgin and BT here in the UK.

Image: NHK

In 2014, it was reported that NHK Science & Technology Research Laboratories had conducted a test of 8K over terrestrial airwaves from its bureau in Hitoyoshi, Kumamoto Prefecture, in southern Japan, and managed to send the 8K Ultra High Definition TV signal to a receiving station 27 kilometers away using a single UHF channel.

Now, at this year's IBC event in Amsterdam,  NHK have revealed that they are working on using the next generation codec that will replace HEVC to distrubute the terrestrial signal. HEVC is currently being rolled out in a number of European countries as part of a switch to all HD broadcasting. But given the high bitrates required by 8K, HEVC is deemed unsuitable, as the 8K image can't be compressed enough.

Instead, it's reported that NHK will be using Versatile Video Codec (VVC), which should allow it to broadcast 8K using 30-35Mbps - within the bandwidth range of a digital terrestrial TV multiplex.

The move to try to broadcast 8K over terrestrial is interesting, as other broadcasters, notably the BBC, appear to be working to ditch terrestrial from 2030, in favour of an all-IP future.